April 17, 2014

Research Notes

Psychiatry awarded $10M NIMH grant

The National Institute of Mental Health has awarded a $10 million, five-year grant to fund the Silvio O. Conte Center for Translational Mental Health Research in the Department of Psychiatry. The center focuses on cortical cells, circuits, connectivity and cognition in schizophrenia.

Schizophrenia is a major public health problem and devastating illness, affecting 0.5-1 percent of the world’s population. Current treatments for schizophrenia have limited effectiveness, and all medications currently used to treat schizophrenia and related disorders were discovered by serendipity. These problems emphasize the need for a new approach to treatment development, similar to that used in other domains of medicine, where drug development begins with the identification of molecular targets based on their role in the pathophysiology of an illness.

Under the direction of faculty member David A. Lewis, the center addresses this challenge by focusing on the mechanisms that link the pathology, pathophysiology and clinical features of schizophrenia. The center’s research activities test the hypothesis that cell type-autonomous molecular disturbances in layer three pyramidal cells of the neocortex give rise to morphological abnormalities in these neurons, the severity of which is moderated by normal differences across cortical regions. This pathology alters cortical circuitry within and between regions, impairs functional connectivity and neural synchrony across regions and disturbs both “bottom up” and “top down” processes during working memory and attention in individuals with schizophrenia.

The center is composed of five research projects and two cores that are designed to provide convergent tests of this hypothesis. The synergism of these projects facilitates a translational approach to schizophrenia research, making laboratory findings readily relevant to clinical treatment.

The center’s work is directed at identifying pathophysiology-based molecular targets for new therapeutic interventions and at developing biomarkers of this pathophysiology that can be used to monitor the efficacy of such interventions. Thus, the center is a multidisciplinary effort directed at testing a mechanistic hypothesis in order to improve the understanding of a core component of the disease process of schizophrenia.

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According to an international team headed by the University of Pittsburgh Cancer Institute (UPCI), a breast cancer therapy that blocks estrogen synthesis to activate cancer-killing genes sometimes loses its effectiveness because the cancer takes over epigenetic mechanisms, including permanent DNA modifications in the patient’s tumor, once again allowing tumor growth.

Researchers reported in the National Institutes of Health (NIH)-funded study, published in the current issue of Science Translational Medicine, that the finding warrants research into adding drugs that could prevent the cancer from hijacking patients’ repressive gene regulatory machinery, which might allow the original therapy to work long enough to eradicate the tumor.

“Resistance to hormonal therapy is a major clinical problem in the treatment of most breast cancers,” said Steffi Oesterreich, a faculty member in the Department of Medical Pharmacology and Chemical Biology. “Through testing of a tumor’s genetic and epigenetic makeup, we may be able to identify the patients most likely to develop such resistance and, in the future, create a treatment regimen tailored to giving each patient the best chance of beating their cancer.”

Epigenetic translates to “above genetic” and is an emerging field of study that looks at how environmental factors — such as infections, pollutants, stress and, in this case, long-term exposure to drugs that block estrogen synthesis — could influence a person’s DNA. Epigenetic changes do not alter the structure of the DNA, but they do change the way the DNA is modified, which subsequently determines the potential of gene regulation.

By performing a genome-wide screen in breast cancer cells, Oesterreich and her colleagues identified a gene called HOXC10 as one that the cancer seems to modify to allow continued tumor growth in patients whose cancer becomes resistant to traditional therapies.

The hormone estrogen represses genes, such as HOXC10, that induce cell death and inhibit growth. About 70 percent of breast cancer tumors are positive for a protein called estrogen receptor alpha, which prevents HOXC10 from killing the cancer. To overcome this, doctors put these patients on anti-estrogen therapy, including aromatase inhibitors.

Unfortunately, in some cases, the tumor uses different epigenetic mechanisms, independent of estrogen, to repress the HOXC10 gene. This allows the cancer to continue growing.

When the tumor uses these mechanisms, it makes deeper modifications to the expression of the patient’s DNA, permanently blocking the HOXC10 and other genes and making cancer treatment much more difficult.

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Two separate projects, spearheaded by Pitt researchers and published recently in scientific journals, represent important steps toward demonstrating on patients the utility of portable, optical brain imaging for concussion and substantiating — via a large-scale statistical analysis — computerized neurocognitive testing for concussion.

The findings from the optical-imaging research, employing functional near infrared spectroscopy (fNIRS), provided preliminary support for the tool as a low-cost, portable device for imaging sports and military concussions, researchers said.

That report, published in Brain Imaging and Behavior, led to further research — an NIH-funded study at Pitt examining the brain during dual cognitive-balance performance in children following concussions.

The fNIRS unit works like a pulse oximeter for the brain. It measures blood flow to the brain by sending light signals from sensors mounted in a 3-pound headcap, then producing images of blood oxygen changes — representing brain activity — by recording the absorption of light at different colors.

The fNIRS produced readouts while participants wearing the bandana-like headcap took a computerized neurocognitive test and matched the test in revealing the brain’s struggles to complete specific cognitive tasks.

“We hypothesize that cerebral blood flow is affected post-injury, and brain processing is going to be less efficient,” explained Anthony Kontos, a faculty member in the Department of Orthopaedic Surgery and assistant research director of the UPMC Sports Medicine concussion program.

“If you’re performing a memory task or reaction-time task, it would require activation — more blood flow, more oxygen needed — in certain areas of the brain specific to that task. However, we found decreased and more spread out activation in the concussed group. In other words, their injured brains were less efficient and strained to get from elsewhere in the brain the resources necessary to perform cognitive tasks.”

Radiology faculty member Theodore Huppert added: “We knew what brain areas normally should light up. From our data set, we had on average decreased brain activity and more diffuse brain activity, where more areas of the brain were needed to accomplish the task because the usual areas weren’t as efficient.”

This preliminary study included nine people ages 18- 45 who recently were symptomatic of sports-related concussion. Researchers compared them to five people who were uninjured. The fNIRS scans indicated that the concussed brain activated at a lower threshold and drew from a wider area, a sharp contrast from earlier functional magnetic resonance imaging (fMRI) studies using concussion patients. And the decrease in oxygenated blood flow and lower test performance were detected during certain more cognitively strenuous aspects of neurocognitive testing: word memory, design memory and symbol matching.

A wireless fNIRS device is expected on the market soon, availing it for further research in a clinical and perhaps a sideline concussion setting, said Huppert, who has worked with and published research on fNIRS for years.

Yet, Kontos underscored the utility of the current iteration: “You can wear this while doing neurocognitive testing, you can wear this during balance-testing, you can even wear it while doing exertional testing, like on a treadmill. It’s usable in an environment for sports-related concussion.”

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Additional link revealed between endometriosis, ovarian cancer

According to a Pitt/UPCI study, in partnership with Magee-Womens Research Institute (MWRI), some women with endometriosis, a chronic inflammatory disease, are predisposed to ovarian cancer, and a genetic screening might someday help reveal which women are most at risk.

At the American Association for Cancer Research 2014 annual meeting, UPCI and MWRI researchers presented the preliminary results of the first comprehensive immune gene profile exploring endometriosis and cancer.

“A small subset of women with endometriosis go on to develop ovarian cancer, but doctors have no clinical way to predict which women,” said senior author

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, a faculty member in obstetrics, gynecology and reproductive sciences and an MWRI researcher. “If further studies show that the genetic pathway we uncovered is indicative of future cancer development, then doctors will know to more closely monitor certain women and perhaps take active preventative measures, such as immune therapy.”

Endometriosis is a painful, often invasive and recurrent condition that happens when the tissue that lines the uterus grows outside of the uterus, causing inflammation. It affects approximately one in 10 women.

By screening tissue samples from women with benign endometriosis (endometriosis with precancerous lesions and endometriosis-associated ovarian cancer), Vlad and her colleagues identified the complement pathway, which refers to a series of protein interactions that trigger an amplified immune response, as the most prominent immune pathway that is activated in both endometriosis and endometriosis-associated ovarian cancer.

Lead author Swati Maruti Suryawanshi, a post-doctoral research fellow in obstetrics, gynecology and reproductive sciences at MWRI, said: “If, as our study indicates, a problem with the immune system facilitates cancer growth through chronic activation of the complement pathway, then perhaps we can find ways to change that and more effectively prime immune cells to fight early cancer, while controlling the complement pathway.”

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Genetic testing beneficial in melanoma treatment, study shows

Genetic screening of cancer can help doctors customize treatments so that patients with melanoma have the best chance of beating it, according to the results of a clinical trial by Pitt researchers.

Results of the NIH-funded trial were presented at the American Association for Cancer Research annual meeting. They showed that the cancer immune therapy drug ipilimumab appears most likely to prevent recurrence in patients whose cancer shows high expression of immune-related genes.

“We’ve reached a point in the treatment of melanoma — and cancer in general — where we’re making major improvements in the outcomes of patients through personalized medicine,” said lead investigator Ahmad Tarhini, a faculty member in the Department of Medicine. “Anti-cancer therapy can be associated with significant side effects and economic costs. Therefore, we have a major interest in the development of tests that may allow us to predict which treatment regimen is most likely to help certain patients, while sparing others the unwanted side effects and cost of medications that are unlikely to work.”

Before and after ipilimumab treatment, Tarhini and his colleagues obtained tumor biopsies used to run genetic tests on the tumors of 32 patients with advanced, stage 3 melanoma. All patients were given standard-of-care surgery, which included complete surgical removal of an advanced tumor.

Patients with tumors that had higher levels of expression of a group of immune-related genes, either before or soon after treatment with ipilimumab, had a 63 percent lower risk of cancer recurrence after surgery.

“By validating these findings in a large national trial that also will allow us to investigate other significant biomarker data, we’ll seek to develop ‘biomarker signatures’ that doctors can use to customize melanoma treatment plans,” said Tarhini. “The ultimate goals of therapy are to best treat the cancer in an individualized approach, while avoiding the unnecessary exposure of patients to severe side effects.”

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Recurrent head & neck tumor gene mutations vulnerable to cancer drug?

An examination of the genetic landscape of head and neck cancers indicates that while metastatic and primary tumor cells share similar mutations, recurrent disease is associated with gene alterations that could be exquisitely sensitive to an existing cancer drug. Researchers from Pitt and Yale University School of Medicine shared their findings during a mini-symposium at the American Association for Cancer Research annual meeting.

About 50 percent of patients diagnosed with head and neck squamous cell cancers already have disease that has spread, or metastasized, to the lymph nodes, explained Jennifer Grandis, a faculty member in otolaryngology and director of the head and neck program at UPCI. About 20-30 percent of patients thought to be cured of the disease go on to develop recurrent cancer, which typically doesn’t respond to standard treatments.

“We decided to compare the genetic signatures of tumor cells from primary tumors with those from disease that had spread and cancers that were thought cured but then came back in the hopes of getting some clues about how best to guide therapy in these different settings,” Grandis said. “We found that recurrent cancers might have an Achilles’ heel we can exploit to kill them.”

The team conducted the first whole-exome genetic sequencing study on what Grandis called its “treasure trove” of frozen patient samples and found similar mutations both in primary tumors and in the lymph nodes to which their cancers already had spread. But there were different mutations in tumors that had recurred after a period of remission that were not found in their original cancers.

“The recurrent tumors carried mutations in a gene area that encodes for DDR2 cell receptors,” Grandis said. “Other studies have shown that DDR2 mutations can confer sensitivity to the cancer drug dasatinib, which could mean that drug has promise in the treatment of recurrent head and neck cancers.”

The researchers suggest that further investigation of dasatinib treatment is warranted.

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Personalized treatment may benefit common breast cancer subtype

According to a multidisciplinary team led by Pitt scientists, the second-most common type of breast cancer is a very different disease than the most common and appears to be a good candidate for a personalized approach to treatment.

Invasive lobular carcinoma, characterized by a unique growth pattern in breast tissue that fails to form a lump, has distinct genetic markers that indicate drug therapies may provide benefits beyond those typically prescribed for the more common invasive ductal carcinoma. The results recently were published in Cancer Research.

Patients with invasive lobular carcinoma typically are treated through surgical removal of the cancer, followed by chemotherapy or hormone therapy or both, usually with the estrogen-mimicking drug tamoxifen or estrogen-lowering aromatase inhibitors, the same as patients with invasive ductal carcinoma.

Lead author Matthew Sikora, a postdoctoral associate in pharmacology and chemical biology, said: “However, recent analyses suggest that a subset of patients with lobular carcinoma receive less benefit from adjuvant tamoxifen than patients with ductal carcinoma.

“Our study, the largest of its kind, indicates an issue with the estrogen receptors inside lobular carcinoma cells and points to potential targets for drug therapy in future clinical trials, which we are developing.”

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Disease-free survival estimates for ovarian cancer improve over time

The probability of staying disease-free improves dramatically for ovarian cancer patients who already have been disease-free for a period of time, and time elapsed since remission should be taken into account when making follow-up care decisions, according to a study led by Pitt researchers.

A patient’s prognosis traditionally is determined when they are diagnosed with a disease or when they become disease-free. However, for patients who already have survived or been disease-free for a number of years, these estimates may no longer be accurate because prognosis usually improves over time.

Determining a prognosis that takes into account time elapsed since remission may be a more accurate benchmark. This measure is known as conditional disease-free survival.

Brenda Diergaarde, a faculty member in epidemiology, said: “Having more accurate information about the risk of recurrence will allow patients and clinicians to make better informed decisions regarding follow-up care after cancer treatment. It also may lead to patients having a better quality of life because a more accurate diagnosis can ease their fears about the cancer coming back.”

Diergaarde presented the findings at the American Association for Cancer Research annual meeting.

In the study, researchers estimated disease-free survival and conditional disease-free survival for 404 ovarian cancer patients who had achieved remission and whose information was collected as part of the hormones and ovarian cancer prediction (HOPE) case-control study. The researchers found disease-free survival estimates for ovarian cancer patients improved dramatically over time, in particular among those with poorer initial prognoses.

At time of remission, the probability of staying disease-free for three more years was 48 percent. This increased to 98 percent for patients who had remained disease-free for five years after remission.

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Pitt researchers have found that an agent that inhibits mitochondrial division can overcome tumor cell resistance to a commonly used cancer drug, and that the combination of the two induces rapid and synergistic cell death. Separately, neither had an effect.

The findings were presented at the American Association for Cancer Research annual meeting.

“In our earlier work, we found that blocking production of a protein called Drp1 stopped mitochondria, known as the powerhouses of the cell, from undergoing fission, which is necessary for the cellular division process called mitosis,” said Bennett Van Houten, the Richard M. Cyert Professor of Molecular Oncology in the School of Medicine and leader of UPCI’s molecular and cell biology program.

“The loss of this critical mitochondrial protein caused the cells to arrest in mitosis and to develop chromosomal errors, and eventually led the tumor cell into the cell death pathway known as apoptosis.”

The researchers blocked Drp1 in breast cancer cell lines with an agent called mitochondrial division inhibitor-1 (mdivi-1) and found that when mdivi-1 and the cancer drug cisplatin were given together, they caused DNA damage, DNA replication stress and greater than expected apoptosis rates.

The synergistic drug combination acted through two independent biochemical pathways that caused the mitochondrial membrane to swell, increasing its permeability and allowing the leak of chemical signals that trigger apoptosis.

“Cisplatin is one of the most widely used cancer drugs today, but some tumors are inherently resistant to it, and many others become resistant, leading to treatment failure,” Van Houten said. “In our studies, this combination overcame cisplatin resistance and caused cancer cell death, which is very encouraging.”

The team is testing the regimen’s effectiveness in a mouse model of ovarian cancer, a disease that often recurs and no longer responds to cisplatin treatment.

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Pitt center joins global task force to address urgent viral threat

Causing victims to suffer severe fever and pain, chikungunya virus has reached the Caribbean and South America and soon is expected to cause outbreaks in the United States. For many years the mosquito-borne virus has remained primarily in Africa, the Indian subcontinent and Southeast Asia. In response to the arrival of the virus in the Western Hemisphere, the University of Pittsburgh Center for Vaccine Research announced that it will be part of the new Global Virus Network (GVN) chikungunya task force, composed of top virologists from around the world. The announcement of the new task force coincided with World Health Day 2014 on April 7.

This year’s theme is vector-borne diseases, which are infections spread to humans through mosquitoes, ticks and other insects. Chikungunya is a vector-borne disease that is spread quickly by mosquitoes. “Viruses are among the leading causes of death and disability in the world. Being able to quickly bring together the most knowledgeable researchers without regard to borders and political agendas to address viral threats such as chikungunya is paramount,” said GVN co-founder and scientific director Robert Gallo, who also is director of the Institute of Human Virology at the University of Maryland School of Medicine.

There is no specific antiviral drug treatment for chikungunya, which can resemble dengue fever, another threatening mosquito-borne infection. Treatment of those infected with chikungunya is directed primarily at relieving symptoms, which include a very high fever and joint pain. The joint pain often is debilitating and, in some cases, persists for several months or years. While chikungunya does not cause death directly, it can contribute to a fatal outcome in people who become infected and have other medical problems.

The GVN chikungunya task force is composed of 16 virologists representing nine countries. William B. Klimstra and Kate D. Ryman, Pitt faculty members in microbiology and molecular genetics, are among those who will represent the United States.

Much of the group’s effort will focus on issues related to more rapid identification of infections, improved treatment options and development of an effective vaccine.

Chikungunya first was described following an outbreak in southern Tanzania in 1952. Since then, the virus has been identified in dozens of countries across Asia, Europe, Africa and now the Americas. A vaccine against chikungunya does not yet exist; however, it is a focus of work at Pitt in both Klimstra’s and Ryman’s laboratories. Ryman recently was lead author on a publication in PLOS Neglected Tropical Diseases, describing a new method for creation of live-attenuated chikungunya vaccines and identification of a promising vaccine candidate. Both researchers also are developing animal disease models for testing of vaccines, as well as therapeutic interventions for chikungunya disease.

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Teen binge drinking, alcohol-brand mentions in pop music linked

Binge drinking by teenagers and young adults is strongly associated with liking, owning and correctly identifying music that references alcohol by brand name, according to a study by Pitt and the Norris Cotton Cancer Center.

Based on a national, randomized survey of more than 2,500 people ages 15-23, the findings suggest that policy and educational interventions designed to limit the influence of alcohol-brand references in popular music could be important in reducing alcohol consumption in teens and young adults. The results are published online in the journal Alcoholism: Clinical & Experimental Research.

“Every year, the average adolescent is exposed to about 3,000 references to alcohol brands while listening to music,” said lead author Brian A. Primack, a faculty member in the Department of Medicine. “It is important that we understand the impact of these references in an age group that can be negatively affected by alcohol consumption.”

Alcohol is considered the third-leading, lifestyle-related cause of death in the U.S., according to the Centers for Disease Control and Prevention.

Of the 2,541 participants who completed the survey, 1,488, or 59 percent, reported having had a complete alcoholic drink, defined as 12 ounces of beer, five ounces of wine or 1.5 ounces of hard liquor, at one time. Of those, 18 percent reported binging — or drinking heavily over a short period of time — at least monthly, and 37 percent reported having had problems, such as injuries, due to alcohol.

In the survey, which could be completed either online or on paper, participants were given the titles of popular songs that included alcohol mentions and asked if they liked or owned the song. They also were tested to determine if they could spontaneously recall what brand of alcohol was mentioned in the lyrics.

Survey participants who could correctly recall alcohol brands in songs had more than twice the odds of having had a complete alcoholic drink, compared to those who could not recall the brand, even after adjusting for factors including age, socioeconomic status and alcohol use by friends or parents. The participants who could identify the alcohol brands in songs also had greater odds of ever having binged on alcohol.

“A surprising result of our analysis was that the association between recalling alcohol brands in popular music and alcohol drinking in adolescents was as strong as the influence of parental and peer drinking and an adolescent’s tendency toward sensation-seeking,” said Primack. “This may illustrate the value that this age group places on the perceived opinions and actions of music stars.”

Primack said that one possible solution could be to empower adolescents with critical thinking skills. “Media literacy is a growing educational methodology that may be successful in helping young people make healthier decisions,” he said. “In the case of alcohol, it may be valuable to help them understand how alcohol-brand references in music may manipulate their thoughts and emotions to sell them a product.”

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Plant-derived anti-cancer compounds explained

Compounds derived from plant-based sources — including garlic, broccoli and medicinal plants — confer protective effects against breast cancer. In multiple presentations at the American Association for Cancer Research annual meeting, Pitt researchers updated the cancer research community on their findings, including new discoveries about the mechanisms by which the plant-derived compounds work.

“In recent years, we’ve made some very encouraging discoveries indicating that certain plants contain cancer-fighting compounds,” said Shivendra Singh, UPMC Chair in Cancer Prevention Research and a faculty member in pharmacology and chemical biology.

“By understanding the molecular mechanisms by which these plant-derived compounds work against breast cancer, we hope to find efficient ways to use them to prevent and fight cancer in patients.”

At the poster session “Mechanisms of Chemoprevention,” Singh oversaw four presentations by faculty members in pharmacology and chemical biology on plant-derived compound discoveries in his laboratory.

He discussed how withaferin A, derived from an Indian medicinal plant, binds to tubulin, a well-known target for drug treatment in breast and other cancers. This compound binds tubulin in the cancer at a site distinct from those affected by other clinically used tubulin targeting agents. Notably, this effect of withaferin A is selective for cancerous breast cells.

Eun-Ryeong Hahm discussed how diallyl trisulfide, an oil-soluble molecule created by chewing allium vegetables, such as garlic, decreases levels of the estrogen receptor-alpha protein in breast cancer cells and inhibits growth of breast cancer stem cells by decreasing levels of two other proteins.

Su-Hyeong Kim described how benzyl isothiocyanate, a molecule found in edible cruciferous vegetables, such as garden cress, works in breast cancer cells to decrease levels of Bmi-1, a protein that controls genes responsible for cell proliferation.

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Detecting infection with a microchip

Alexander Star, a faculty member in chemistry, and his team have developed a microchip that may save joint implants before they’re ruined by infection.

Star believes that this chip, which is engineered to detect pH levels in the body, will be able to alert doctors to encroaching bacterial infection, which causes acidosis, a drop in pH levels in nearby tissue.

The chip, festooned with tiny carbon nanotubes (engineered segments of carbon that are efficient electrical conductors) and treated with a proprietary polymer, reads pH levels and transmits the information to a radio frequency identification reader held by a doctor. The wirelessly powered chip can be attached to implants and can stay in the body for the long term.

One in 100 Americans has an artificial joint, Star says, “and bacterial infections are a common complication of the implant.” Infection can damage the body surrounding the implant, and bacterial films, resistant to antibiotics, can colonize the implant itself. Catching infection early without having to resort to invasive measures could lead to faster treatment. “This is a very attractive detection mechanism for monitoring the condition of the implant,” Star says. “It may alleviate the need for further surgical intervention.”

A paper on Star’s pH chip recently was published online in Scientific Reports.

—Compiled by Alex Oltmanns

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The University Times Research Notes column reports on funding awarded to Pitt researchers as well as findings arising from University research.

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